1. Field of the Invention
This application relates to surgical systems and assemblies that include an access device for minimally invasive surgery, and in particular relates to systems and devices that provide access to a surgical location, e.g. adjacent a spine, for one or more instruments to perform a procedure at the surgical location. More particularly, this application relates to an apparatus which can be used to retain bone portions, such as vertebrae of a spinal column, in a desired spatial relationship.
2. Description of the Related Art
An apparatus for retaining vertebrae of a spinal column in a desired spatial relationship includes a longitudinal member extendable along the spinal column. A fastener engageable with a vertebra of the spinal column connects the longitudinal member to the vertebra. A housing has a first passage through which the longitudinal member extends and a second passage with a longitudinal axis extending transverse to the first passage. The fastener extends through an opening in the housing into the second passage. The longitudinal axis of the fastener is positionable in any one of a plurality of angular positions relative to the longitudinal axis of the second passage.
A spacer received in the housing is engageable with the fastener and the longitudinal member. A clamping member threadably engages the housing to clamp the longitudinal member, the spacer, and the housing to the fastener to prevent movement of the fastener relative to the housing.